cornell



FFICE.

JNO. B. CORNELL, OF NEW' YORK, N. Y.

DOUBLE-CYLINDER FIREPROOF COLUMN.

Specification of Letters Patent No. 27,528, dated March 20, 1860.

To all whom it may concern:

Be it known that I, Jol-IN B. CORNELL, of the city, county, and State of New York, have invented a new and Improved Fireproof Column; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings, making a part of this specification.

It is a well known fact that cast iron columns, when formed in the ordinary manner, are greatly weakened and sometimes utterly destroyed .by the action of water when the said columns are in a highly heated state. This serious objection to cast iron columns caused me to institute a series of experiments in the hope of being able to produce an architectural column that would possess all the advantages of the ordinary cast iron column, without any of its defects. My said experiments resulted in the production of an architectural column composed of two thin sided concentric tubes (a and Z1) of cast iron, combined with each other by means of a solid mass of fire-proof composition run into the annular space between said tubes.

The united weight of the metallic tubes (a and b) of my improved colinnn, need not be greater than the weight of the ordinary east iron column; and the thickness of the lire-proof composition (0,) between the said tubes, need be only suiiicient to afford the requisite protection to the inner tube, (2),)`

in case the outer tube (ca) should be eX- posed to the action of lire in a burning building.

The inner tube (b) of my said improved column, must be strong enough to safely support the entire weight that would be brought to bear upon it, in case the outer tube (a) of said column, should be injured by the action of lire and water.

The outer tube a, of my said improved column, having very thin sides, has much greater strength in proportion to its weight than the ordinary cast iron column; and another result of the thinness of the sides of the said outer tube, is that it will endure the action of lire and water with much less danger of injury than the ordinary thicksided cast iron column for architectural purposes. As cast iron has but little strength save at or very near to its surface, it will readily be perceived that my improved architectural Vcolumn must possess fully three times the stiffness and strength of an ordinary cast iron column containing the same amount of metal.

The tubular metallic portions a, of my improved architectural column, may be made of any angular shape instead of the circular shape represented in the accompanying drawings.

That I claim as my invention and desire to secure by Letters Patent, is-- Constructing an architectural column of two concentrically arranged cast iron tubes and an intermediate solid mass of lire-proof composition, when the said parts are combined with each other in such a manner as to form but a single article of manufacture which shall possess the characteristics herein set forth.

The above specification of my double cylinder fire-proof column, signed and witnessed this 27th day of July 1855.

JOI-IN B. CORNELL.

l/Vitnesses W'LLLIAM W. CORNELL, CHARLES H. FIELD. 

